How can I get my dad to understand he needs to allow people to end a conversation they are having?

I agree with Sweetstuff. My daughter used to tell my Mom she had to go to work. She never said the word home.

Some how signal the person Dad is talking to "they" need to cut off the conversation. If ur visiting, the host needs to say "Well it be a nice visit but we have another engagement" or "we have an early morning, so time for us to go to bed".

Hi Lisa. You can’t reason with someone with dementia. The person that is trying to leave just needs to say good bye “Mr So and so”. See you again soon and leave. No intervening by you or others as this appears to upset him. Good luck.

Hi LisaDawn, has your dad ever been formally given a cognitive exam by a doctor? If so and he is impaired I don't know why your sister is in such denial. It would be cruel for her to treat him as if he wasn't. You may need to do some gentle educating for everyone's sake. As for his unwillingness to end a discussion I've not dealt with this but others on this forum may have. One thing is to warm visitors in advance that he has this tendency and they will just have to exit even if he thinks the convo is still going. Or you can redirect his attention to allow visitors to "escape". Let us know what you find that works.